Process of manufacturing zinc



UNITED STATES PATENT OFFICE;

HENRY AUGUST HUNICKE, OF ST. LOUIS, MISSOURI.

PROCESS OF MANUFACTURING ZINC.

SPECIFICATION forming part of Letters Patent No. 393,832, dated December 4, 1888. Application filed December 2, 1887. Serial No. 256,731. (No specimens.)

To all whom it may cmwern:

Be it known that I, HENRY AUGUST HU- NICKE, of St. Louis, Missouri, have made a new and useful Improvement in a Process of Manufacturing Zinc, of which the following is a full, clear, and exact description.

The invention, which is an improved process of zinc-reduction, is based on the fact that metallic zinc is oxidized by carbonic acid (00,) between the temperature at which zinc volatilizes and the temperature at which carbonic monoxide (CO) reduces zinc oxide (ZnO) and that above the last-named (reduction) temperature metallic zinc is not oxidized by carbonic acid and no reaction occurs.

I11 carrying out the process the ore to be reduced and the fuel, which serves to supply both the reducing agent and the means for maintaining the reduction temperature, are immediately associated within the reductionchamber, as thereby the operation of reducing zinc is rendered more continuous and economical, the appliances employed are not worn out as rapidly, and various grades of ores can be readily and successfully treated in the reducing-chamber.

To this end the process consists as follows: The ore to be reduced, together with a proper amount of suitable fiuxing material, but separate from the fuel to be used within the reduction-chamber, must be heated in an oxidizing atmosphere to the temperature for reducing zinc before introducing-it into the reduction-chamber.- The fuel used within the reduction-chamber, together with a proper amount of fluxing material, is similarly preheated. The two, (the ore and the fuel,)as well as the flux mentioned, at the temperature described, are then passed into the reductionchamber, wherein, and by means of a suitable supply of air introduced into the reductionchamber for the purposes of the fuel combustion therein, the ore (ZnO) combines with the carbonic monoxide generated from the burning fuel at a temperature at which carbonic monoxide reduces zinc oxide, and zinc in the form of a vapor is produced. The temperature maihtained within the reduction-chamber should in practice exceed that at which zinc oxide is reduced, in order thereby to have the entire interior of the reduction-chamber, including the outlet leading to the condenser, so heated as notto be chilled below the zinc-oxide reduction point whenever the reduction-chamber is opened to receive the ore and fuel, and so that the zinc-vapor, when once generated, shall not be chilled below the Zinc-reduction point, and by reason of the carbonic acid present be reconverted into zinc oxide. The process is completed by transferring the Zincvapor to a condenser and there converting it into liquid zinc as rapidly as it practicably can be done. Successive lots of ore and fuel and flux are introduced into the reductionchamber as fast as those previously introduced are treated, and meanwhile the airsupply is kept up, the air-supply in practice being an air-blast such as employed in many forms of cupola-furnaces, but suitably graduated, so as not only to furnish the requisite amount to the fuel, but, on the other hand, not to cause such an extreme pressure outward as to carry the zinc-vapor too rapidly through the condenser, so as to be ultimately carried off with the other gases. The slag is drawn off below the zone of fusion. The volatilized zinc is constantly going to the condenser, which is constructed and operated to effect the liquefaction of the zinc in the shortest possible time. The other gaseous current-s proceeding from the cupola, which, saying the outlet to the condenser, is substantially a closed chamber, pass with the zinc through the condenser, and are finally discharged through an outlet separate from that for the liquefied zinc..

By preheating, as described, the ore and fuel, and especially by preheating the ore, the temperature of the reduction-chamber, especially at the immediate points where the zinc-oxide is reduced, is not chilled below the reducing-temperature, so as to cause reaction and zinc oxide to be formed within the reduction-chamber, and by condensing the zincvapor as speedily as is practicable the zinc oxide, which otherwise'is liable to form at that point, is in amount reduced to a minimum. A novel feature of -,the condensingis the application of cold, the greater the degree of cold the better, and thereby effecting the condensation of the zinc-vapor in the speedy manner described.

The construction which I regard as being best adapted for carrying out this improved process of zinc-reduction is described and claimed in a separate application for Letters Patent this day executed by me.

I claim- 1. The herein-described process of manufacturing zinc, the same consisting in preheating the ore, fuel, and flux separately, as described, then introducing them so heated, together with air, into a reduction-chamber, and therein, and at the temperature at which carbonic monoxide reduces zinc oxide, combining the ore and carbonic monoxide and producing Zinc-Vapor, and then, Without allowing the temperature of the zinc to drop, transferring it to a condenser and there liquefying it.

2. The herein-described process of manufacturing zinc, the same consisting in prei HENRY AUGUST HUNICKE.

\Vitnesses:

C. D. MooDY, GEO. J. CHAPMAN. 

